Stents are tubular support structures that may be implanted into body vessels to treat blockages, occlusions, narrowing ailments and other problems that may restrict flow through the vessel. Numerous vessels throughout the vascular system, including peripheral arteries, such as the carotid, brachial, renal, iliac and femoral arteries, and other vessels, may benefit from treatment by a stent. Generally, a stent comprises a framework of interconnected struts that allows the stent to be collapsed into a low profile configuration for delivery into the vessel and then radially expanded at the treatment site to support the vessel wall. Balloon-expandable stents expand in response to the inflation of a balloon, whereas self-expanding stents deploy automatically when released from a delivery device.
In some instances it may be necessary to remove a stent or other medical device that has been implanted in a vessel. The stent may have been deployed improperly (e.g., not fully expanded), for example, or positioned at an undesirable location in the vessel. To safely and successfully retrieve a device under these circumstances, open surgery is usually needed.